Granulomas are comprised of MTB in the center that is housed by the macrophage that initially engulfed it with lymphocytes, fibroblasts, and additional macrophages forming the outside. Neutrophils then come along and release enzymes at the MTB’s new home. These enzymes are able to digest a portion of the outer wall but they do not reach the MTB inside. This results in caseous (cheesy) lesions that eventually heal through calcification. So it appears that every time the immune system attacks MTB it only adds to the bacteria’s protection. Part of MTB’s ability to resist destruction (and why it’s not initially destroyed by alveolar macrophages) includes mycolic acid found in the lipid membrane that gives it a wax-like surface. If the host becomes
